Commanders are desperately looking for new ways to defeat improvised explosive device (IED, or roadside bombs) that is the biggest killer of U.S. solders in Iraq. In the last month, IEDs have come to account for 60 to 70 percent of U.S. combat deaths and 90 percent of those killed and wounded in Iraq. For a long time before that, IEDs only accounted for about a third of combat deaths. The Pentagon set up the Joint IED Defeat Task Force in early summer to consolidate efforts to defend against roadside explosives and car bombs. It now has around 85 people, including four field teams that are dividing their time between Iraq and Afghanistan. U.S. troops currently only detect about one-third of IEDs before they go off and about 20 IEDs a day go off in Iraq.

Anti-IED hardware is being sent to Iraq as rapidly as it can be created. The Army has sent over 700 Warlock electronic bomb jamming devices to Iraq and Afghanistan to interfere with radio signals used for remote device triggering. The Marine Corps has five "change-detection" systems in Iraq that use imagery gathered from helicopter and UAV platforms fed into computers to compare terrain and scenery. Changes that might indicate the emplacement of an IED a freshly dug-up patch next to the side of a road, for example -- are highlighted and can either be further investigated or avoided. Acoustic sensors are also being used to triangulate the location of IED explosions and mortar fire.

One senior general has called on space-based methods to track down IEDs, calling the devices "idiotic technology." One idea is to find ways to pinpoint IED explosions in order to cue other sensors around the area to locate the people detonating them and "kill them." Exactly how this would be done using existing technology is very unclear, since less than a dozen optical and radar imaging satellites only spend a handful of minutes per day over Iraq and there are at least several hours involved between taking images and having them processed and shipped out to field commanders. Infrared satellites originally designed for detecting intercontinental ballistic missile launches were used during Operation Iraqi Freedom to pick up the heat signatures of smaller Scud-type missiles to provide both early warning of incoming attacks and cue Patriot missile batteries for interception. Would such sensors be sensitive enough to detect a larger IED explosion in ground clutter? Would they be accurate enough to pinpoint an explosion within a useful range? If so, mechanisms to relay that data in real time to theater commanders already exist. Doug Mohney